1. Field of the Invention
The present invention relates to an interior illumination lamp and, for example, to an interior illumination lamp to be mounted to a door, a ceiling, or the like of a motor vehicle.
2. Related Art
In the related art, an interior illumination lamp is shown in FIG. 10, for example, Unexamined Japanese Patent Publication 2000-1141.
The interior illumination lamp is to be used by mounting to a back door of a station wagon, and is adapted to illuminate a luggage room provided at the rear or the lower part of the opened back door of the station wagon by changing the direction of illumination.
As shown in FIG. 10, an interior illumination lamp 100 includes a lamp housing 102 mounted to a trim 101 defining a wall surface of the back door, and a circular opening 103 provided forwardly of the lamp housing 102. A lamp supporting member 104 having a spherical inner surface is provided rearwardly of the opening 103 (rightward in FIG. 10), and a lamp body 105 in the shape of partial sphere is provided inside the lamp supporting member 104 so as to be change in direction by 360° within a predetermined range. The lamp body 105 includes a bulb 106 disposed therein, and a lens member 107 projecting from the opening 103 of the lamp housing 102 provided on the front surface (left surface in FIG. 10). A space S is provided between the lens member 107 and the opening 103 so as to constrain the amount of rotation of the lamp body 105.
In the above-described interior illumination lamp 100, the direction of the lamp body 105 having the bulb 106 attached thereon can be changed by 360° within the predetermined range, and the change of direction is performed by moving the lens member 107 by hand. In this case, in such the interior illumination lamp 100, fixation of the lamp body 105 which is directed to a desired direction is normally achieved by frictional resistance of felt provided between the inner surface of the lamp supporting member 104 and the outer surface of the lamp body 105. Therefore, there is a problem such that when the resiliency of the felt is reduced by exposure to a high temperature or deterioration with age, the lamp body 105 cannot be fixed at the desired direction.
In order to cope with this problem, usage of a spring and a ball which are little affected by the temperature or deterioration with age is also conceivable. However, in this case, the number of parts increases, and hence the cost is increased correspondingly, and the structure becomes complex.